Color television transmitter



Dea 2, 1941. y w FLECHSlG u 2,264,748

COLOR TELEVISION TRANSMITTER Filed July 1l 1959 /Pawee Mam/5 INVENTOR.

A WERNER FLECHS/G BY WW/ff WM ATTORNEYS.

Patented Dec. 2, 1941 COLOR TELEVISION TRANSMITTER Application July 11, 1939, Serial'No.1283,7r48= In Germany July 11,1938

Claims.

My Iinvention relates to a method and means for producing televisionimages in natural colors, and v.relates particularly to the picture analysis for this purpose.

.It has been proposed to segregate the image of :thenobject to be transmitted into two or three images 7with the fundamental colors red, blue and yellow.; to transmit signals corresponding to these color components simultaneously over separate channels or successively over a common channel. As a 4picture analyzing tube, so-called storage tubes :have been proposed which are well-known in the art. In such arrangements it is provided tosplit the optical .image into several images in accordance with the color components and to provide a separate analyzing tube for each color component. This procedure involves an increased amount Aof apparatus and considerable operating diiliculties, as will be evident to those skilled in the art.

It is .the object of this invention to overcome the aforesaid disadvantages and diiculties and to provide for a simple method and means for producing-picture signals for television in colors, including the use of so-called storage tubes. The invention shall now be explained in detail in connection with the drawing, which schematically shows an embodiment of the invention reduced to the simplest terms. I indicates a vacuum receptacle housing a storage electrode 2, an electron gun 3 and two sets of deflecting plates 4 and 5. Such a tube may be the well-known Iconoscope or one of the various types of storage tubes known in the art. A first optical image of an object indicated by arrow 'l is produced in the plane indicated by dotted line Il by means of schematically indicated optical system 8. A light lter is arranged in plane Il, which may, for instance, consist of an endless film possessing adjacent film frames with diierent colors, whereby the color sequence is cyclically recurrent. The individual film frame should be of the same dimensions as the optical image produced in the plane Il. The light transmitted through the filter then goes through an optical system I0 by means of which a second image is projected upon storage member 2, which image consists of ltered light.

In operation, a iirst or intermediate image of the object 1 to be tr-ansmitted is projected by means of the optical system 8 in plane Il. In this plane, filter nlm 9 is moved in vertical direction. The size of the individual lter sections covers at least the entire optical image produced in plane ll. It will be seen that certain color components are transmitted, while othersarezattenu-ated, wherebythe spectral range vof fatt-,enuation and. transmission is shifted with each filter section offdiierent color. Thus, the second image `.projected `upon storage member 2 by means of optical system vIt) consists of filtered light. Storage member 2..is scanned by a defined electron beam produced by electron gun 3 and deected in two dimensions by means of deflecting plates d and 5,: as `is common practice inthe television art. It is intended to make full use -of the entire storage time, which,at 30 `television images persecond, lis 349,0 second.- At the beginning of a frame scansion, the scanning :beam .may be at the upper left-.hand corner of the scanned area of photocathode 2. At this vtime a ilter section of nlm 9 is fully coincident with the first or intermediate optical image in plane Il so that the entire pictured area on-the-storage member 2 is of uniform color. As the scanning beam progresses from top to,bottom,.the .endless `iilter lm 9 lis also moved from topto bottom, whereby the boundary between adjacent .filter sections of dilerent colors may lag the scanning .beam Aby a, short distance only. Assume that a red. image was projected upon storage member 2 during a certain interval and that this red image is just being scanned. The iilter section of the iilm adjacent to the red one may be blue. As the scanning beam progresses downward in Vertical direction, the lter lm is moved in the same direction, whereby the image of the boundary between red and blue filter sections on the storage member is made to follow the scanning beam within a short distance. This may readily be accomplished by interlocking the scanning generators with the A. C. power mains, as is standard practice in television, and to drive the lter lm by a synchronous motor. A mechanical device located between the shaft of the synchronous motor and the drive shaft of the lm sprocket enables shifting the relative position of the two shafts in respect to each other. Such devices are well-known in the art and can be used for adjusting the proper phase conditions between scanning beam and nlter nlm motion.

While I have described my invention in connection with an endless lm plate carrying iilter sections of different colors, it may be understood that I do not wish to be limited to this particular means of color filtering, the broad idea of the invention being that a first or intermediate image of an object to be transmitted is produced in a plane; that certain color components of this image are transmitted while others are attenuated; and that a second image consisting of the transmitted light is projected upon a storage member which is scanned. Thus, it may be seen that modifications and changes of a preferred embodiment of my invention may be made well within the scope of my invention, as will be understood by those skilled in the art.

What I claim is:

1. In combination, means for forming in a plane a rst optical image of an object to be transmitted, light filtering means comprising unicolored areas of image area in said rst plane covering said iirst image, means placed in the path of said light rays transmitted through said iiltering means for forming a second optical image of said object in a second plane, a member of image area capable of storing energy'in said second plane, means for successively scanning elemental areas of said member to produce a picture signal, and means for moving said light ltering means, whereby the color of the light incident upon said last-named areas is changed shortly after the scanning of said areas.

2. In combination, means for forming in a plane a first optical image of an object to be transmitted, light filtering means in said plane covering said image, means placed in the path of said light rays transmitted through said ltering means for forming a second optical image of said object in a second plane, a member of image area capable of storing energy in said second plane, means for successively scanning elemental areas of said member to produce a picture signal, means for moving said ltering means in consonance with the scansion of said member, whereby the color of the light incident upon said lastnamed areas is changed shortly after the scanning of said areas.

3. In combination, means for forming in a plane a first optical image of an object to be transmitted, a plurality of different colored light filters of image area located in said plane and covering said image, means in the path of the light rays transmitted through said filtering means for forming a second optical image of said object in a second plane, a member of image area capable of storing energy in said second plane, means for scanning said member in two directions to produce a picture signal, and means for continuously moving said filtering means across said first optical image in the direction of one of said scanning motions and in consonance therewith, whereby the color of the light incident upon elemental areas of said energystoring member is changed shortly after the scanning of said areas.

4. Method of producing picture signals for color television, comprising the steps of successively projecting certain color components only of the image of the object to be transmitted Vupon a multitude of elemental areas of a member capable of storing energy, scanning said elemental areas one by one in successive order, and changing the color components of the light incident upon each of said elemental areas shortly after scansion of each of said areas.

5. Method of producing picture signals for color television, comprising the steps of forming in a plane a rst optical image of the object to be transmitted, transmitting only a portion of the light spectrum for a portion of the area of said first image, transmitting only another portion of the light spectrum for the remaining portion of the area of said rst image, using said transmitted light to form a second optical image of said object on a member capable of storing energy located in a second plane, scanning said member to produce a train of picture signals and varying the ratio of the portions of said first image area at the same rate as the variation of the ratio of unscanned-to-scanned area of said member is effected and in consonance therewith, whereby the color of the light incident upon elemental areas of said energy-storing member is changed shortly after the scanning of said areas.

WERNER FLECHSIG. 

